Method and/or apparatus for analyzing the content of a surveillance image

ABSTRACT

An apparatus comprising an input circuit, a content analyzer, a storage circuit and an output circuit. The input circuit may be configured to generate a first intermediate signal from a plurality of input video signals. The content analyzer circuit may be configured to present one or more flags in response to the intermediate signal. The storage circuit may be configured to (i) store and organize the first intermediate signal into a plurality of sequences each related to one of the input video signals and (ii) generate a second intermediate signal from the sequences. The output circuit may be configured to generate an output video signal in response to the second intermediate signal. The output circuit may be configured to embed tracking information into the output video signal in response to the one or more flags.

FIELD OF THE INVENTION

[0001] The present invention relates to surveillance imaging generallyand, more particularly, to a method and/or apparatus for analyzing thecontent of a surveillance image.

BACKGROUND OF THE INVENTION

[0002] Conventional surveillance systems typically implement multiplecameras to monitor a site. The systems are often archived to tape orother storage media for future reference. Archiving typically uses acontinuous operation and generates large amounts of video data. Storing,monitoring, retrieving, and analyzing such large volumes of stored videodata presents challenges to conventional storage systems. Videocompression, and more specifically motion-compensated video compression,such as the system described in co-pending application U.S. Ser. No.10/389,314, entitled MULTI-CHANNEL VIDEO COMPRESSION SYSTEM, which ishereby incorporated by reference in its entirety, may be used to reducethe processing overhead of video monitoring systems.

[0003] It would be desirable to implement image processing functions toimprove the volume of storage, accuracy of monitoring, and/or ease ofretrieval and analysis of archived video content.

SUMMARY OF THE INVENTION

[0004] The present invention concerns an apparatus comprising an inputcircuit, a content analyzer, a storage circuit and an output circuit.The input circuit may be configured to generate a first intermediatesignal from a plurality of input video signals. The content analyzercircuit may be configured to present one or more flags in response tothe intermediate signal. The storage circuit may be configured to (i)store and organize the first intermediate signal into a plurality ofsequences each related to one of the input video signals and (ii)generate a second intermediate signal from the sequences. The outputcircuit may be configured to generate an output video signal in responseto the second intermediate signal. The output circuit may be configuredto embed tracking information into the output video signal in responseto the one or more flags.

[0005] The objects, features and advantages of the present inventioninclude providing a method and/or apparatus for implementing videosurveillance that may (i) analyze the content of a surveillance image,(ii) provide efficient implementation of a combined content analyzer andvideo encoder, and/or (iii) implement an encoder system that may provide(a) spatial and temporal filtering, (b) spatial and temporal analysis,(c) motion estimation, (d) motion compensation, (e) video capture and/or(f) storage subsystems that may be used by a content analyzer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] These and other objects, features and advantages of the presentinvention will be apparent from the following detailed description andthe appended claims and drawings in which:

[0007]FIG. 1 is a block diagram of a multi-channel encoder system;

[0008]FIG. 2 is a block diagram of a multi-channel encoder system;

[0009]FIG. 3 is a block diagram of a multi-channel encoder systemimplementing content analysis in an intelligent image pre-processor;

[0010]FIG. 4 is a block diagram of a system illustrating a contentanalyzer implementation in a decoder;

[0011]FIG. 5 is a diagram illustrating the data flow of the presentinvention;

[0012]FIG. 6 is a diagram of a display side system;

[0013]FIG. 7 is a diagram of a system implementing two output streams;and

[0014]FIG. 8 is a diagram of a single channel implementation of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The present invention may provide content analysis that may beintegrated in the acquisition side of a surveillance system (e.g.,during recording, either with or without encoding), the retrieval sideof a surveillance system (e.g., during playback) or in both theacquisition and retrieval sides. Factors such as system hardware,installation, labor costs, regulatory or legal restrictions, and goalsand value of the surveillance content may influence whether all of thesystems or individual systems described are implemented.

[0016] The present invention improves upon conventional approaches byimplementing content analysis in the acquisition side of the system. Thevolume of data recorded can be reduced by identifying and eliminating“uninteresting” content. An example of uninteresting content may be longperiods of time where nothing changes in the image being recorded.Similarly, monitoring accuracy may be improved by identifying “alert”conditions, calling attention to “interesting” (or potentiallyinteresting) content. Interesting content may be defined as the portionof a stored data where a monitoring attendant should determine if anaction is needed. Calling attention to interesting content may be ofparticular significance when the attendant is unmotivated, distracted,busy, bored, or for some other reason inattentive. System hardware maybe implemented more efficiently and accurately by responding to periodsand regions of interest or indifference to improve accuracy (eithertemporal or spatial) of acquisition. Also, interesting features may betracked within the acquired content. Control or informational signalsmay be presented to external systems.

[0017] On the playback side, large volumes of acquired data can bequickly navigated through to locate regions of interest for display,transmission, and/or subsequent analysis. The benefits of playbackacquisition is that all data is acquired without discarding data beforestorage. The parameters or rules for determining what is deemedinteresting content may be set at playback. The present invention mayimplement either or both of record content analysis and playbackcontent, analysis. When the analysis accompanies a system with anencoder, additional implementation efficiency may result. In particular,image and motion analysis and storage systems of an encoder may beadapted to provide content analysis. Such encoding may be implementedwithout additional system complexity and cost.

[0018]FIG. 1 and FIG. 2 illustrate multi-channel encoder systems withoutcontent analyzers. Such systems may be useful for single channelsystems, in which case the multi-channel input multiplexer would be asimple video capture module. The encoder systems of FIG. 1 and FIG. 2are described in co-pending application U.S. Ser. No. 10/389,314,entitled MULTI-CHANNEL VIDEO COMPRESSION SYSTEM, which is herebyincorporated by reference.

[0019] Referring to FIG. 3, an example of a system 100 illustrating anembodiment of the present invention is shown. The system 100 illustratesa multi-channel encoder system with content analysis in an intelligentimage pre-processor is shown. The system 100 illustrates an exampleimplementation that builds on the design illustration in FIG. 1.However, the system 100 may also be built on the system of FIG. 2.

[0020] The system 100 generally comprises an input section (or circuit)102, a storage section (or circuit) 104, an output section (or circuit)106, and a content analyzer block (or circuit) 107. The system 100 mayreceive multiple signals (e.g., INPUT1-INPUTk, where k in an integer) atinterfaces 108 a-108 k, respectively. The system 100 may have an output109 that may generate a signal (e.g. OUTPUT). The signal OUTPUT may be abitstream. The system 100 may also have an output 111 that may generatea signal (e.g., TRACK). The signal TRACK may include event information.

[0021] The content analyzer 107 may present image sequences to the datastorage unit 104 through a number of busses 112 a-112 n. The contentanalyzer may also present event information at an output 114. Thecontent analyzer 107 may receive a signal (e.g., INT) from the circuit102. The content analyzer may also have an input 116 that may receive anoptional external input (or sensor) signal.

[0022] The input section 102 may be implemented as a multi-channel inputmultiplexer and temporal decimator. Each of the inputs 108 a-108 kgenerally receives one of the input signals INPUT1-INPUTk, sometimesreferred to as channels or bitstreams. Each input signal INPUT1-INPUTkmay be implemented as a video signal. The input video signalsINPUT1-INPUTk may each have a similar video format or have differentvideo formats. The input section 102 may multiplex the input videosignals INPUT1-INPUTk onto a video line 110 as the intermediate signalINT1. The intermediate signal INT1 may be implemented in a standardvideo format. Multiplexing operations within the input section 102 maybe provided by a variety of methods as described in the previouslyreferenced co-pending application.

[0023] The storage section 104 may be implemented as a memory device.For example, the storage section 104 may be implemented as a computerhard disk drive, a memory device, or other appropriate memory. Thememory section 104 may be configured to organize pictures received viathe intermediate signal INT1 into separate sequences 114 a-114 k (wherek is an integer), one sequence for each of the input channel videosignals INPUT1-INPUTk. The storage section 104 may generate anintermediate signal (e.g., INT2). The intermediate signal INT2 mayincorporate picture data from each of the sequences 112 a-112 k. Theintermediate signal INT2 may be implemented in a standard video formatsuitable for compression by the output section 106.

[0024] A storage capacity for each sequence 112 a-112 k may be basedupon one or more parameters associated with the respective input videosignal INPUT1-INPUTk. For example, similar memory space may be allocatedto buffer each of the sequences 112 a-112 k where each of the inputvideo signals INPUT1-INPUTk have similar resolutions, frame rates, andpriorities. In another example, larger storage capacity may be allocatedto a particular channel where the associated input video signal INPUThas a higher resolution, higher frame rate and/or higher priority thanthe other input video signals INPUT1-INPUTk.

[0025] The output section 106 may be implemented as an encoderconfigured to encode and/or compress a set of pictures (e.g., an MPEG2group of pictures (GOP)) from each of the sequences 114 a-114 k withinthe intermediate signal INT2. The resulting encoded and/or compressedsignal may be presented as the output video signal OUTPUT. The outputsection 106 may be operational to encode/compress the sequences 114a-114 k in a rotating pattern. For example, the output section 106 maycompress some or all of the first sequence 114 a, then some or all ofthe second sequence 114 b, then some or all of the third sequence 114 c,and so on. After operating on the final sequence 114 k, the outputsection 106 may wrap around and operate on the first sequence 114 a.Other orderings for encoding/compression may be implemented to meet thecriteria of a particular application.

[0026] In one embodiment, the output section 106 may group pictureswithin a particular sequence 112 separately from all the pictures in allother sequences 114 a-114 k. The pictures within each of the sequences114 a-114 k may be compressed with references only to other pictures inthe same sequence 112 a-112 k. Illustratively, an output section 106implementing an MPEG2 encoder may compress the pictures from each inputvideo signal INPUT1-INPUTk as separate closed groups of pictures.Therefore, long periods of low or no-motion video may be captured andmotion compensated compression schemes (e.g., MPEG1, MPEG2, MPEG4,H.261, H.263, H.264, etc.) may be applied to achieve extremely efficientcompressions. In the above example, the output section 106 may havegroups of pictures of different lengths or structure depending on thetemporal decimation ratio and/or other application criteria. The system100 may also include an image compositor 124 (for generating a digest orPicture in Picture (PIP) stream for viewing multiple channelssimultaneously) and/or an image decimator.

[0027] In one example, the content analyzer 107 may be incorporated inthe output circuit 106. The content analyzer 107 processes the incomingimages by performing both spatial and temporal analysis noted by thebi-directional arrows between the content analyzer 107 and the memorysection 104. The system 100 is shown illustrating fewer pictures in thequeues for channels CH1 and CH3. The content analyzer 107 has suppressedimages judged uninteresting for a particular implementation. Thedifferent frame rates on the different channels CH1-CHK may also resultfrom the configuration of the input multiplexer system 102 (e.g., notexclusively from the result of content analysis). Typically these willbe images that have zero (or sufficiently low) change relative to theprior encoded image. Consequently there is insufficient new informationto warrant encoding the repeated image and consuming channel bandwidthor storage capacity. The system 100 also optionally provides a minimumencoding update rate (e.g., encoding a minimum number of pictures perunit of time) to demonstrate that the system 100 is functioning properlyduring extended periods of uninteresting video.

[0028] The channel CHK, on the other hand, illustrates a queue with morepictures than some of the other channels. The content analyzer 107 hasidentified content of greater interest and has increased theimage-encoding rate on the channel CHK to provide greater temporalresolution during periods of interest. The system can optionallygenerate one or more digest streams 122 a-122 k of a digest picture 124.The digest picture 124 may be presented for viewing while the sequences114 a-114 k may be stored. The digest picture 124 may have a border ofchannel K highlighted, under control from the content analyzer 107 anduser configuration rules. An example of an alert may be accomplished inany one of a variety of ways and combinations. For example, an alert maybe generated as an audio alert, a test message, a highlighted picture inpicture (PIP) stream. Furthermore, such an alert may be used to (i) movea stream of interest to the front of a video picture, (ii) display afull resolution image sequence, (iii) generate a message to present tosystem, and/or (iv) control the start, stop, pause or resume of therecording.

[0029] An event log (e.g., EVENT INFORMATION) may be transmitted alongwith the video. The EVENT INFORMATION may be either encoded directlyinto the bitstream or as a separate data stream within a multi-channelmultiplexer 102. In one example, the EVENT INFORMATION may be storedlocally, while the image sequences 114 a-114 k may be stored remotely.The EVENT INFORMATION may be transmitted as one or more flags. The EVENTINFORMATION assists operators in navigating directly to periods ofinterest when viewing and analyzing archived material. The EVENTINFORMATION may be implemented as index data that may be storedseparately from the archived video through the signal TRACK presented atthe output 111. In particular, if the archiving device is non-randomaccess (e.g., a tape device), having an event log stored to a randomaccess device (e.g., a hard disk drive or memory) may increaseproductivity when navigating through the archive. The event informationis typically augmented by the encoder and multiplexer system 106 toembed additional navigation information (e.g., intra picture location)which the content analyzer 107 does not have available. Additionally,within the archiving system, the event log may be augmented withstorage-related navigation information, such as file name, location, andoffset within the file. An offset may include a logical block number, asector, cylinder, head or drive, a physical position on a tape, or otherplacement indicator use by a storage device. Standard log information(e.g., date and time, source number, etc.) may also be implemented tomeet the design criteria of a particular implementation.

[0030] Referring to FIG. 4, an alternate system 100′ is shown. Thesystem 100′ illustrates a multi-channel decoder system with anintelligent content analyzer. The circuit 106′ may be implemented as adisplay and video scaling/compositing circuit. The solid output linelabeled OUTPUT may be used for video for monitoring. The dashed outputline labeled TRACK may provide event information. The content analyzer107 may be located in the decoder 102. The system 100′ addresses thecase where it is desirable (e.g., for cost, system simplicity,commercial, safety or regulatory reasons) to perform analysis at thedownstream or receiving side of the system. In this case, the contentanalyzer may be in the monitoring site. The analysis may be used toprovide alerts to attendants or other automated equipment.Alternatively, the analysis may be used at an archival site. An eventlog may be generated in real time as the streams come in. The analysismay be employed during subsequent analysis to assist as a filter to getthrough the large amount of recorded material. In this latter case, thesystem 100′ may be configured to specifically look for certaincombinations of events. For example, motion in a certain region of agiven camera at night (e.g., period of relative darkness) may be used.In the scenario described, the system 100′ may perform the sameprocessing after decoding as the encoder system 100 of FIG. 3 performedprior to encoding.

[0031] Referring to FIG. 5, a process 200 is shown. The process 200 mayillustrate content analysis and identification of spatial regions ofinterest. The process 200 generally comprises an acquisition block (ormodule) 202, a content analyzer block (or module) 204, an optionalprocessing block (or module) 206, and an optional encoding block (ormodule) 208. The encoding block 208 may be implemented as amulti-channel encoding block. The content analysis may be implementedeither separately or in conjunction with the identification of temporalregions of interest described. The content analyzer block 204 generallyidentifies a region of interest (e.g., a car moving in a parking lot).The region of interest is generally conveyed to the image processingmodule 206. The image processing module 206 may implement digital zoomor image enhancement such as brightness, contrast, or edge enhancementoccurs.

[0032] The image processing module 206 may also track the motion ofregions of interest. Such tracking may be used either (i) in conjunctionwith the processing described above and/or (ii) in order to provideinformation or control signals to external devices. For example, if theacquisition block 202 has a motorized mount and can be steered, controlinformation or signals may be provided to improve the acquired sourcesignal provided to the encoder. Some of the parameters that may becontrolled by the acquisition device 202 include controls the camera(e.g., zooms in or out, or changes brightness, contrast, or edgeenhancement settings as desired) or to acquire the region of interestwith better temporal and/or spatial resolution. Such analysis may beapplied to one or more channels within the system either independentlyor simultaneously. For example, a single camera in a retail environment(e.g., a store) may be positioned to maintain a wide focus duringgeneral operations. If motion is detected near a point of interest(e.g., the cash register), the system 200 may be configured to changefocus (e.g., either with or without motorized camera mounts, as dictatedby cost and location) to acquire the immediate vicinity of the registerwith greater resolution.

[0033] The content analysis and actions described may be performed in avariety of ways. For example, content analysis may be performed onuncompressed video (e.g., for alert and event log generationinformation), even in the case where no video compression is performed.The acquisition features may be implemented in the context of the system100 of FIG. 3, but without the encoder in the output portion 106.

[0034] Furthermore, an input multiplexer (as in FIG. 1) could beinserted between the camera and content analyzer for the handling ofmultiple inputs. The dotted line showing control of the camera by thecontent analyzer 204 applies to controllable acquisition systems and maynot be needed for all implementations. The image processing stage 206 isoptional and may not be used in all embodiments. In the image processingstage 206, digital crop and zoom could occur, as well as otherprocessing such as brightness, contrast, and edge enhancement. The block208 may transmit uncompressed video or include a multi-channel encodersystem with multiple outputs to multiple destinations (as described inFIG. 7).

[0035] Referring to FIG. 6, a circuit (or system) 100″ is shownillustrating a display side system. The block (or circuit) 102″ may beimplemented as a multi-channel demultiplexer. While multiple inputs areshown, the input to the demultiplexer 102″ may be received from either asingle source or a multi input source. For storing multiple videochannels onto a single video tape, for instance, only a single videoinput is needed. However, for systems with large numbers of videochannels, multiple storage systems may be implemented. Channels storedon different tapes may be needed for playback time processing. Thesystem 100″ may be applied, for instance, in a situation where theoutput video is transmitted uncompressed and stored to one or more taperecording systems (e.g., VHS). Both capture side and playback sidesystems may be implemented either together or separately. In a captureside case, the system 100″ provides all the processing described in theabove claims.

[0036] The system 100″ illustrates a multi-channel demulitplexer anddisplay system with intelligent image sequence analyzer. The solidoutput line from the circuit 106″ may be used for video for monitoring.The dashed output line may provide event information. An optional userinput may be used to control the circuit 106″. The circuit 106″ mayprovide multiple output streams that may be presented to multipledestinations.

[0037] Referring to FIG. 7, a system 100′″ illustrating a multi-streamsurveillance system is shown. The system 100′″ may provide support forheterogeneous processing of separate streams for monitoring and/orarchiving. The system 100′″ generally comprises the input section (orcircuit) 302, a decimator section (or circuit) 304, adecimator/compositor section (or circuit) 306, an encoder section (orcircuit) 308, a processing section (or circuit) 310 and a monitoringstation (or display circuit) 312. The encoder section 308 generallycomprises the storage section 104, the output section 106 and themultiplexer 120 as shown in FIG. 3. The storage section 104 may beadapted to receive two intermediate signals (e.g., INT1H and INT1L)substantially simultaneously.

[0038] The intermediate signal INT1 may be received by both thedecimator section 304 and the decimator/compositor section 306. Thedecimator section 304 may be operational to generate the signal INT1Hfrom an intermediate signal INT1 presented by the input section 302. Thesignal INT1H may be a high spatial output resolution video signal. Thedecimator/compositor section 306 may be operational to generate thesignal INT1L from the intermediate signal INT1. The signal INT1L may bea low spatial output resolution video signal, relative to the signalINT1H. The signal INT1L may be a time-multiplexed stream of each inputvideo signal INPUT1-INPUTk. The signal INT1L may include a composite,picture-in-picture, index and/or similar stream having decimatedpictures from several of the input video signals INPUT1-INPUTk.

[0039] Generation of the high-resolution signal INT1H may involvehorizontal decimation, vertical decimation, temporal decimation, or nodecimation at all. Similarly, generation of the low resolution signalINT1L may be achieved using any of the above decimation methods. The lowresolution signal INT1L may also be a digest of lower resolutionpictures from the other input video signals INPUT1-INPUTk. In oneembodiment, several input video signals INPUT may be (i) decimated by ½both horizontally and vertically, generating source input format (SIF)pictures and (ii) further decimated temporally to generate updatedpictures on the order of once per second. The decimator section 145 mayinsert one or more still frames at a non-decimated and/or higherresolution into the high-resolution signal INTIH.

[0040] The encoder section 308 may be configured to receive, buffer,encode and multiplex each of the intermediate signals INT1H and INT1L.The multiplexer 120 within the encoder section 308 may generate multipleoutput video signals (e.g., OUTPUTH and OUTPUTL) from the encodedversions of the intermediate signals INT1H and INT1L, respectively. Theoutput video signal OUTPUTH may have a spatial and/or temporalresolution higher than that of the output video signal OUTPUTL. Theencoder section 148 is shown generating two output video signals OUTPUTHand OUTPUTL for diagrammatic simplicity, although (as shown in FIG. 2) ahigher number of output video signals may be generated.

[0041] The output video signals OUTPUTH and OUTPUTL may be sent todifferent locations for further processing. In one embodiment, theoutput video signal OUTPUTH may be transferred to the processing section310. The processing section 310 may be configured to perform additionaloperations on the output video signal OUTPUTH before forwarding to asubsequent section. For example, the subsequent section may be a storagesystem for archiving the high resolution output video signal OUTPUTHpermitting later retrieval and analysis.

[0042] The output video signal OUTPUTL may be transferred to themonitoring station 312 for real-time viewing. The output video signalOUTPUTL may optionally be transferred to the processing section 310 (asindicated by the dashed arrow). Archiving the signal OUTPUTL may providea way to quickly identify a reference time that a particular event wascaptured by one or more of the cameras. The reference time may thenprovide a starting point for viewing the appropriate high-resolutionpicture or pictures.

[0043] One stream may be implemented for archiving and subsequentretrieval and another stream may be implemented for live monitoring. Thecontent analyzer (107 in FIG. 3) is generally engaged to adapt thestreams sent to the monitoring station in response to the content beingacquired and other optional external data inputs (e.g., sensor inputindicating a door has opened) Illustratively, this system may beimplemented to send only the digest stream if no interesting content ispresent, but switch to the camera of interest when motion is detected.Alternatively, the digest stream may be highlighted or the systembandwidth to the monitoring station increased and some or all camerassent to the monitoring station (312). Additionally, audio or otherelectronic signals may be generated.

[0044] The monitoring circuit 312 may be located at a remote location.An example is the case where the recording system (tape, disk, etc.) islocal, but provides access to a remote location. The surveillancesystem, as an example, could have a telephone modem. The system 100′″may respond to an alarm to ‘call out’ to the monitoring station 312 andsend a digital signal (motion detected). Alternatively, the system 100′″may send video data at appropriate spatial and/or temporal resolution.If compression is available, the system 100″ may send the digital signalcompressed at the appropriate bit rate. In one example, a wireless, DSL,cable modem, or other high speed data connection may be implemented.

[0045] The content analyzer in the encoder circuit 308 may control theparameters of the stream sent to the monitoring station 312. Alarms ordifferent video streams may be sent to the monitoring station 312. Forexample, in the absence of interesting content (e.g. motion), themonitoring station 312 may receive only the digest stream(s). Whenmotion or an alarm is detected, however, some or all of the streams maybe transmitted to the monitoring station 312.

[0046] Referring to FIG. 8, an example of a single channel processingoperation is shown. The input multi-channel multiplexer of FIGS. 3 and 7is omitted for simplicity. FIG. 8 illustrates the ability to add thecontent analyzer (and all the various benefits described) to a(multi-channel) surveillance system with little to no additional cost.All of the multi-stream multiplexer and multi-destination featuresdescribed may be implemented, but have omitted for diagrammaticsimplicity.

[0047] In one embodiment, the content analyzer may be implemented insoftware, taking results from the motion and temporal/spatial processorsas well as external inputs, and controlling both the encoder system andpre-processing stages. The system 100′″ may also implement optionalcompression in the block 308. FIG. 8 illustrates re-use of the imagespatial/temporal analysis, motion estimation, and image storage units.Additional content may be integrated with pre-processing but is shown asa separate block in the diagram to illustrate that it is not limited tostandard encoder temporal/spatial analysis.

[0048] As used herein, the term “simultaneously” is meant to describeevents that share some common time period but the term is not meant tobe limited to events that begin at the same point in time, end at thesame point in time, or have the same duration.

[0049] While the invention has been particularly shown and describedwith reference to the preferred embodiments thereof, it will beunderstood by those skilled in the art that various changes in form anddetails may be made without departing from the spirit and scope of theinvention.

1. An apparatus comprising: an input circuit configured to generate afirst intermediate signal from a plurality of input video signals; acontent analyzer circuit configured to present one or more flags inresponse to said intermediate signal; a storage circuit configured to(i) store and organize said first intermediate signal into a pluralityof sequences each related to one of said input video signals and (ii)generate a second intermediate signal from said sequences; and an outputcircuit configured to generate an output video signal in response tosaid second intermediate signal, wherein said output circuit isconfigured to embed tracking information into said output video signalin response to said one or more flags.
 2. The apparatus according toclaim 1, wherein said content analyzer circuit (i) discriminates betweensequences of greater interest to the application and (ii) presents theresult of said discrimination to said output circuit in said one or moreflags.
 3. The apparatus according to claim 2, wherein said contentanalyzer changes a recording frame rate according to the result of thediscrimination.
 4. The apparatus according to claim 2, wherein saidcontent analyzer enforces a minimum frame rate for storing each of saidsequences.
 5. The apparatus according to claim 1, wherein said pluralityof sequences comprise channels of greater interest and channels oflesser interest, wherein said channels of greater interest are storedusing a higher bit rate than said channels of lesser interest.
 6. Theapparatus according to claim 1, wherein said output circuit generatesspecific audio, video, control, or recording actions based on said oneor more flags.
 7. The apparatus according to claim 6, wherein one ofsaid actions comprises an audio alert.
 8. The apparatus according toclaim 6, wherein one of said actions comprises generating a textmessage.
 9. The apparatus according to claim 6, wherein one of saidactions comprises generating a highlighted stream.
 10. The apparatusaccording to claim 6, wherein one of said actions comprises bringing astream of interest to the front of said output video stream.
 11. Theapparatus according to claim 6, wherein one of said actions comprisesdisplaying a full resolution image sequence.
 12. The apparatus accordingto claim 6, wherein one of said actions comprises generating a datamessage to present to another processing or monitoring system.
 13. Theapparatus according to claim 6, wherein one of said actions comprisescontrolling a start, stop, pause or resume of said storing.
 14. Theapparatus according to claim 1, wherein said content analyzer determinesone or more locations of interesting events within the sequences,wherein said locations are stored in a log.
 15. The apparatus accordingto claim 14, wherein said one or more locations comprise a time stamp ina tape storage device.
 16. The apparatus according to claim 14, whereinsaid one or more locations comprise a file offset in an optical,magnetic, or tape storage device.
 17. The apparatus according to claim14, wherein said one or more locations are generated in response toanalysis of the content of said intermediate signal.
 18. The apparatusaccording to claim 14, wherein said one or more locations are generatedin response to other inputs to the system.
 19. The apparatus accordingto claim 14, wherein said log is transmitted along with the output videosignal.
 20. The apparatus according to claim 14, wherein the storagecircuit is augmented by the log to facilitate retrieval.
 21. Theapparatus according to claim 1, wherein the content analyzer circuitdiscriminates between regions of greater interest within a givenchannel.
 22. The apparatus according to claim 21, wherein said contentanalyzer circuit applies special processing and marking to said regionsof greater interest.
 23. The apparatus according to claim 21, whereinsaid content analyzer circuit performs digital image enhancement on saidregions of greater interest.
 24. The apparatus according to claim 21,wherein said content analyzer circuit further tracks motion of saidregions of greater interest.
 25. The apparatus according to claim 21,wherein said content analyzer circuit issues information or controlsignals to a controller configured to steer a camera toward said regionsof greater interest.
 26. The apparatus according to claim 25, whereinsaid control signals are configured to control (i) zooming in or out,(ii) changes to brightness, (iii) changes to contrast, and (iv) edgeenhancement settings.
 27. The apparatus according to claim 25, whereinsaid control signals are configured to acquire the regions of greaterinterest with better temporal and/or spatial resolution.
 28. Theapparatus according to claim 1, wherein said flags are configured tocontrol one or more channels within the system (i) independently when ina first mode and (ii) simultaneously when in a second mode.
 29. Theapparatus according to claim 1, wherein said input video signals areprocessed in uncompressed form.
 30. The apparatus according to claim 1,wherein said output circuit is configured to generate multiple outputstreams.
 31. The apparatus according to claim 1, wherein said outputcircuit is configured to adapt the composition and contents of one ormore of the output video streams in response to said one or more flags.32. The apparatus according to claim 31, wherein said output circuit isconfigured to send an embedded alarm in one or more of the output videosignals.
 33. The apparatus according to claim 1, wherein said outputcircuit is configured to generate one or more second output videosignals only in response to said one or more flags.
 34. The apparatusaccording to claim 33, wherein one or more of said output video signalsis augmented by additional external data.
 35. The apparatus according toclaim 1, wherein said output video signal comprises a first one or moreof output video signals that are compressed and a second one or more ofvideo signals that are uncompressed.
 36. The apparatus according toclaim 1, wherein said content analyzer circuit and video encoder areconfigured to respond to (i) spatial and temporal filtering, (ii)spatial and temporal analysis, (iii) motion estimation, and (iv) motioncompensation.
 37. The apparatus according to claim 1, wherein saidapparatus (i) presents index information for viewing by a monitoringstation and (ii) stores said output video signal in a data storagesystem.
 38. The apparatus according to claim 1, wherein said flags arestored separately from said plurality of sequences.
 39. The apparatusaccording to claim 1, wherein (i) a first set of said plurality ofsequences is stored locally and (ii) a second set of said plurality ofsequences is stored remotely.
 40. An apparatus comprising: a contentanalyzer circuit configured to present one or more flags in response toa plurality of input video signals; a storage circuit configured to (i)store a plurality of input video signals; and an output circuitconfigured to generate a plurality of output video signals in responseto said stored input video signals, wherein said output circuit isconfigured to embed tracking information into said output video signalsin response to said one or more flags.
 41. An apparatus for analyzingthe content of a surveillance image comprising the steps of: (A)generating a first intermediate signal from a plurality of input videosignals; (B) presenting one or more flags in response to an analysis ofsaid intermediate signal; (C) storing said first intermediate signalinto a plurality of sequences each related to one of said input videosignals; (D) generating a second intermediate signal from saidsequences; and (E) generating an output video signal in response to saidsecond intermediate signal, wherein tracking information is embeddedinto said output video signal in response to said one or more flags.